Concentration of ores by flotation



Patented lit/liar. 20, 1923.

U H t ROYER LUCKENBACH, OF BROOKLYN, NEW YORK, ASSIGNOR TO LUCKENBACH PROCESSES, INC, OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OF NEVADA CONCENTRATION OF ORES BY FLOTATION.

N Drawing.

To all whom it may concern:

Be it known that I, RoYER LL'GKENBACH, a

citizen of the United States, and a resident of the borough of Brooklyn, county of Kings, city and State of New York, have invented a certain new and useful Concentration of Ores by Flotation, of which the following is a specification.

The invention relates to the concentration of ores by flotation and has for its objects to use a cheap and effective reagent which will not only attract and be attracted by the mineral values in the pulp, but will also 'form a copious froth of greatdryness capable of supporting and floating a relatively large amount of mineral particles. but will reject the earthy or gangue particles, whereby a clean concentrate may be formed.

A further object is to use a reagent of which such an infinitesimal amount is employedthat its presence in the concentrate will not materially affect subsequent steps in the recovery and manufacture of the values, and which is itself of such little value, that its recovery need not be attempted.

These and further objects will more fully appear in the following specification and claims.

In the flotation process of ore concentration as at present carried out, coal tar, and coal tar creosote are largely employed as gathering agents. Such substances are not freely miscible in water, and in order to be of any effect in the flotation machine they must first be beaten into the pulp, or the water of the pulp, by vigorous agitation in order to break the tar or creosote up into globules which'will enter into the pulp in the flotation machine and form the emulsion, so called, which apparently is necessary in the carrying out of the oil flotation process.

By means of the present invention, coal tar, coal tar creosote, wood tar and wood tar creosote are formed into a colloid solution, and may be placed in the flotation machine without further treatment, and will produce in the pulp a perfect emulsion.

In carrying out the preferred embodiment of the invention coal tar, or coal tar creosote is mixed with a soluble ketone and the mixture is dissolved in a solution of an alkali in water.

alcohol (ethyl, methyl, or denatured), or

Serial N0. 363,865.

carbon di sulphide may be used as the tar or creosote solvent.

The preferred alkali for use in the mixture is caustic soda, but other alkalies, 01' carbonate of soda, may be used.

If desired the reagent may be acidified by adding an acid, such for example as sulphuric acid, to the reagent until the alkali is neutralized. This acidified reagent is particularly adapted for use with ores of an acid nature.

In the preferred embodiment of the invention, 10 cc. of coal tar, or coal tar creosote, and 5 cc. of ethyl acetate are mixed in warm water with stirring. This forms a more or less syrupy liquid which is preferably diluted with 180 cc. of warm water. This is the reagent. The temperature of the water should be less than the boiling point.

Instead of employing coal tar or coal tar creosote as above, a mixture of 5 cc. of coal tar and 5 cc. of creosote may be used. The combined coal tar and creosote mixture is preferred as such mixture emulsifies better than either alone.

In carrying out the process approximately 8 cc. of the reagent is employed per 1 gallon of water in the pulp. The reagent is miscible in the water, and will immediately spread throughout the pulp.

In a test 500 grams of a New Mexican chalcopyrite copper ore was treated in a Janney flotation machine, with 8 cc. of the reagent in 1 gallon of water.

The ore assayed 4.04% copper.

The machine was run for 4 minutes and a thick, dry, fine grain froth was removed from the surface of the pulp. The concentrate of this froth weighed 65.9 grams and assayed 15.15% copper.

A further run of 3 minutes was made and another froth produced. The middlings. solid content of this second froth weighed 140.3 grams, and assayed 6.62% copper.

The tailings weighed 291.5 grams and assayed 0.33% copper.

The extraction shown in the test was 94.4?- of the copper content of the ore.

The creosote, or other active substance which is comprised in the reagent is, by reason of the reaction with the ketone and the alkali, reduced to extremely fine particles each of which is capable of attracting. or being attracted by, themineral values in the pulp, and will form, orbe incorporated grained froth on the surface of the pulp.

in, the films of the bubbles by the aeration of the pulp, and will rise to the surface bearing, the mineral particle or particles adhering thereto and form a thick, tenacious and fine The proportions above given are approximate only. Some ores, or some runs of the .same-ore, may require a stronger reagent surface and coalescing into a film. The coal tar and creosote as commonly used. in the oil flotation process are indifferent frothersand are usually supplemented by a frothing oil, and a frothing oil, such as used in flotation is an expensive commodity.

By the invention of this application the gathering or collecting properties of the tar and creosote are greatly increased, and the mixture osse'sses the added property of producing a copious froth, which will be clean As will be seen in the example given above the reagent is composed very largely of water, and the proportion of the other materials entering into its composition are almost infinitesimal in comparison to the water and ore in the pulp.

If desired the reagent may be compounded in greatly condensed form by reducing the water content. This will provide for cheap transportation. In use, however, it will, because of the minutenessof the quantity of the active materials used in the pulp, be

' possible to dilute the. mixture whereby rough measurement. as to the quantity to be used, may be made.

It is 'to-be understood thatinstead of coal tar, or'wood tar or their creosotcs, shale tar and some, at least, of its derivatlves may be employed, and that in this specification andclaims the term oily distillate is intended to mean any of them. It is further to be understood that whilethe distillates above mentioned are normally oils, or of an oily nature, they have nothing of an oily nature when reduced and neutralized as above described, and that there is no free oil used in carrying out the process of the application.

In accordance with the provisions of the patent statutes the principle of the invention, has been described together with the process which is now considered to represent the best embodiment thereof, but it is understood that the process described is merely illustrative, and that the invention may be carried out in other Ways.

Having now described the invention what is claimed and desired to be secured by Letters Patent of the United States, is-

1. The process of concentrating ore, which comprises mixing the ore with water to form a pulp, introducing a reagent comprising the reaction product of coal tar and coal tar creosote and a ketone and caustic soda into the pulp, aerating the pulp to form a froth, and removing the froth from the pulp.

2. The process of concentrating ore, which comprises mixing the ore with water to form a pulp, introducln'g a reagent comprising an acidified reaction product of coal tar and coal tar creosote and a ketdiie and caustic soda into the pulp, aerating the pulp to form a froth,.and removing the froth from the pulp.

3. The process of concentrating ore which .consists in mixing the. ore with water to form a pulp, introducing a reagentcomprising thereaction product of coal tarand coal tar creosote and a ketone, mixed with a solution of an alkali in water, aerating the pulp to form a froth, and removing the froth from the pulp.

This specification signed and" witnessed this fourth day of March, 1920.

ROYER LUCKENBACH.

Witnesses:

. J. F. COLEMAN,

"A. EjRE-m'orr. 

